In a known manner, a motor vehicle comprises a plurality of electronic computers each for monitoring or controlling pieces of vehicle equipment.
Thus, a vehicle comprises, for example, an engine control computer in order to control the operating parameters of the engine (such as, for example, the injection of the fuel into the engine cylinders), a computer for commanding the system for regulating the speed of the vehicle, etc.
Conventionally, an electronic computer is in the form of a box in which a printed circuit is mounted, to which are connected the pieces of equipment at the input of the circuit if they provide information to the electronic computer or at the output of the circuit if they are commanded by the electronic computer.
Such a printed circuit comprises, in a known manner, a microcontroller and a plurality of digital connection modules for connecting each piece of equipment to the microcontroller, each digital connection module being connected to a digital input port of the microcontroller.
Depending on the nature and the operation of the pieces of equipment which are connected to the computer, some of the connection modules should allow a digital input for connection to the supply battery of the vehicle (in this case, the digital connection module is said to be in a “pull up” configuration) and others should allow a digital input for connection to the ground (in this case, the digital connection module is said to be in a “pull down” configuration).
To reduce the costs, an electronic computer is designed such as to be usable in various motor vehicles or with various configurations for connecting to pieces of equipment. Yet, depending on the vehicle or the connecting configuration, the type of configuration of each connection module (“pull up” or “pull down”) can vary.
To solve this problem, a known solution consists in making each digital connection module configurable in the “pull up” or “pull down” mode, for example via the manufacturer of the vehicle during the factory construction.
One existing solution for a printed circuit 1A is described with reference to FIGS. 1 and 2. For the purpose of clarity, a single digital input port 110 of the microcontroller 10 and a single digital connection module 20A linked to the digital input port 110 have been shown.
The digital connection module 20A firstly comprises a connector 210 for linking to a piece of equipment 2 of the vehicle and a connecting link 220 for linking the digital connection module 20A to the associated digital input port 110.
To process the signals flowing between the equipment 2 and the microcontroller 10, the digital connection module 20A comprises:                an input capacitor Ce connected firstly to the linking connector 210 and secondly to the ground M,        a first output resistor Rs1 connected firstly to the linking connector 210 and secondly to the digital input port 110 of the microcontroller 10 via the connection link 220,        a second output resistor Rs2 connected firstly to the digital input port 110 of the microcontroller 10 via the connecting link 220 and secondly to the ground M,        an output capacitor Cs connected firstly to the digital input port 110 of the microcontroller 10 via the connecting link 220 and secondly to the ground M.        
To configure the type of the digital connection module 20A, a diode package 230A is mounted on the printed circuit 1A between the input capacitor Ce and the first output resistor Rs1. This diode package 230A comprises two diodes 231A-1, 231A-2, linked to one another at a midpoint 232, and orientated identically in order to conduct the current between a high point 233 and the midpoint 232 or between the midpoint 232 and a low point 234, the midpoint 232 of the diode package 230A being connected to the linking connector 210.
To allow the configuration of the digital connection module 20A type, two locations P1, P2 are provided to receive an input resistor Re.
To this end, routing electric tracks are provided for each of the locations P1, P2. The first location P1 is thus linked firstly to the battery B voltage of the vehicle and secondly to the high point 233 of the box 230A whereas the second location P2 is linked firstly to the low point 234 of the box 230A and secondly to the ground M.
The diode package 230A can thus be connected either at the high point 233 to the battery B of the vehicle via the input resistor Re when the latter is mounted on the first location P1 (as illustrated in FIG. 1), or at the low point 234 to the ground M via the input resistor Re when the latter is mounted on the second location P2 (as illustrated in FIG. 2).
Thus, depending on the type of the digital connection module 20A desired by the manufacturer for the equipment 2 to be connected, the input resistor Re is mounted on one of the locations P1, P2 of the printed circuit 1A, for example during the construction of the electronic computer, in order to link the connector 210 of the digital connection module 20A to the battery B of the vehicle or to the ground M, respectively.
However, such a solution has disadvantages. Indeed, the printed circuit A1 of an electronic computer is a circuit containing many electrical components, particularly at the inputs thereof. Therefore, such a solution requiring the provision of two locations P1, P2 is complex as it requires the provision of double the routing of electrical tracks, which further requires a considerable space on the epoxy board on which the circuit is printed and all the more so since the number of digital inputs 110 is high, for example greater than eight as standard.